While various types of medical tubing arrangements have been previously devised, particularly for withdrawing blood from donors and replacing the red cells such as shown in U.S. Pat. No. 3,782,382, there has long been a need for an improved and simplified infusion set whereby at least two different drugs may be simultaneously administered to a patient, while also permitting the withdrawal of blood samples from the patient without completely disconnecting the infusion set from the source of medication, and without removing and replacing the needle from the patient's vein. In this regard, all previous intravenous infusion sets of which I am aware have been composed of a single length of tubing extending from the venipuncture needle and terminating a female adaptor which connects the single tube to a source of medication or other intravenous fluid.
Alternatively, plastic Y-fittings have been attempted in order to provide a secondary means of injecting a second drug as by inserting a needle from a second drug source through a self-sealing portion of the Y-fitting. However, this limits the use of the infusion set to the number of Y-fittings, and requires disconnection and/or removal from the patient in order to withdraw a blood sample.